Inhibition of long-distance movement of RNA silencing signals in Nicotiana benthamiana by Apple chlorotic leaf spot virus 50 kDa movement protein.
Apple chlorotic leaf spot virus 50 kDa movement protein (P50) acts as a suppressor of systemic silencing in Nicotiana benthamiana. Here, we investigate the mode of action of P50 suppressor. An agroinfiltration assay in GFP-expressing N. benthamiana line16c (GFP-plant) showed that P50 could not prevent the short-distance spread of silencing. In grafting experiments, the systemic silencing was inhibited in GFP-plants (scion) grafted on P50-expressing N. benthamiana (P50-plant; rootstock) when GFP silencing was induced in rootstock. In double-grafted plants, GFP-plant (scion)/P50-plant (interstock)/GFP-plant (rootstock), the systemic silencing in scion was inhibited when GFP silencing was induced in rootstock. Analysis of P50 deletion mutants indicated that the N-terminal region (amino acids 1-284) is important for its suppressor activity. In gel mobility shift assay, P50 lacks binding ability with siRNAs. These results indicated that P50 has a unique suppressor activity that specifically inhibits the long-distance movement of silencing signals.
Yaegashi
Hajime
H
The United Graduate School of Agricultural Sciences, Iwate University, Morioka 020-8550, Japan.
Tamura
Akihiro
A
Isogai
Masamichi
M
Yoshikawa
Nobuyuki
N
D001483:Base Sequence; D052677:Flexiviridae / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology; D049452:Green Fluorescent Proteins / Q000235:genetics; D008970:Molecular Weight; D010935:Plant Diseases / Q000235:genetics / Q000821:virology; D053830:Plant Viral Movement Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D030821:Plants, Genetically Modified; D011485:Protein Binding; D034622:RNA Interference; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics; D017384:Sequence Deletion; D015398:Signal Transduction; D014026:Nicotiana / Q000235:genetics* / Q000821:virology*
D053830:Plant Viral Movement Proteins; D018749:RNA, Plant; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; D049452:Green Fluorescent Proteins